B-1 cells produce natural Abs which provide an integral first line of defense against pathogens while also performing important homeostatic housekeeping functions. In this study, we demonstrate that programmed cell death 1 ligand 2 (PD-L2) regulates the production of natural Abs against phosphorylcholine (PC). Naive PD-L2-deficient (PD-L2(-/-)) mice produced significantly more PC-reactive IgM and IgA. This afforded PD-L2(-/-) mice with selectively enhanced protection against PC-expressing nontypeable Haemophilus influenzae, but not PC-negative nontypeable Haemophilus influenzae, relative to wild-type mice...

BACKGROUND: Brucella has been known to cause pyrexia of unknown origin. CASE CHARACTERISTICS: 9-year-old boy with fever and abdominal pain; multiple abscesses within the liver on ultrasonography. OBSERVATIONS: IgM Antibodies against Brucella were raised in his serum sample, and Brucella serum agglutination test was positive. Immunological work-up suggested selective IgA deficiency. Reduction in size following treatment with trimethoprim-sulphamethoxazole, amikacin and doxycycline...

PURPOSE: Primary selective IgM deficiency (sIgMD) is a primary immunodeficiency with unclear pathogenesis and a low number of published cases. METHODS: We reviewed clinical and laboratory manifestations of 17 sIgMD patients. Serum IgM, IgG, and its subclasses, IgA, IgE, antibodies against tetanus toxoid, pneumococcal polysaccharides and Haemophilus influenzae type b, isohemagglutinins, and T and B lymphocyte subsets, expressions of IgM on B cells and B lymphocyte production of IgM were compared with previously reported case reports and a small series of patients, which included 81 subjects in total...

Immunoglobulin A deficiency is the most common primary immunodeficiency defined as decreased serum level of IgA (less than 7 mg/dl) in the presence of normal levels of other immunoglobulin isotypes. Most individuals with IgA deficiency are asymptomatic and identified coincidentally. However, some patients may present with recurrent infections, allergic disorders and autoimmune manifestations, such as diabetes mellitus, Graves disease and celiac disease. The international literature has not produced any kind of review yet about intra-oral manifestations of selective IgA-deficiency...

BACKGROUND: The ability of anti-cytokine antibodies to play a disease-causing role in the pathogenesis of immunodeficiencies is widely accepted. The aim of this study was to investigate whether autoantibodies against BAFF (important B cell survival signal), APRIL (important plasma cell survival signal), or Interleukin-21 (important cytokine for immunoglobulin class switch) present an alternative mechanism for the development of the following primary antibody deficiencies (PADs): common variable immune deficiency (CVID) or selective IgA deficiency (sIgAD)...

We describe a novel functional role for the HLA-B locus mediated by its intron-encoded microRNA (miRNA), miR-6891-5p. We show that in vitro inhibition of miR-6891-5p impacts the expression of nearly 200 transcripts within the B-lymphoblastoid cell line (B-LCL) COX, affecting a large number of metabolic pathways, including various immune response networks. The top affected transcripts following miR-6891-5p inhibition are those encoding the heavy chain of IgA. We identified a conserved miR-6891-5p target site on the 3'UTR of both immunoglobulin heavy chain alpha 1 and 2 (IGHA1 and IGHA2) transcripts and demonstrated that this miRNA modulates the expression of IGHA1 and IGHA2...

Trisomy 13 (T13) is a congenital chromosomal disorder that is usually fatal within 2 years of birth, and only a few patients have been reported to reach adolescence. Here, we report a male long-term survivor of T13, currently 15 years of age, with a several-year history of extensive acne conglobata (AC) with abscesses on the face and neck. Methicillin-resistant Staphylococcus aureus was consistently isolated from the pustular lesions. Serum IgM levels were extremely low at 10 mg/dl. There were no abnormalities in neutrophil and total B cell number, or in serum IgA and IgG levels...

BACKGROUND/AIM: IgA deficiency is the most common human primary immunodeficiency. The prevalence of allergic disorders and autoimmunity is thought to be increased in selective IgA deficiency (sIgAD). However, it is currently unclear if these disorders coincide within these families. We aimed to evaluate the frequency of allergic and autoimmune disorders in children with sIgAD and their first-degree relatives (FDRs). MATERIALS AND METHODS: The study included 81 children diagnosed with sIgAD and 274 of their FDRs...

Chronic Obstructive Pulmonary Disease is the third leading cause of death in the US, and is associated with periodic exacerbations, which account for the largest proportion of health care utilization, and lead to significant morbidity, mortality, and worsening lung function. A subset of patients with COPD have frequent exacerbations, occurring 2 or more times per year. Despite many interventions to reduce COPD exacerbations, there is a significant lack of knowledge in regards to their mechanisms and predisposing factors...

Peripheral spondyloarthritis (SpA) is a common extraintestinal manifestation in patients with active inflammatory bowel disease (IBD) characterized by inflammatory enthesitis, dactylitis, or synovitis of nonaxial joints. However, a mechanistic understanding of the link between intestinal inflammation and SpA has yet to emerge. We evaluated and functionally characterized the fecal microbiome of IBD patients with or without peripheral SpA. Coupling the sorting of immunoglobulin A (IgA)-coated microbiota with 16S ribosomal RNA-based analysis (IgA-seq) revealed a selective enrichment in IgA-coated Escherichia coli in patients with Crohn's disease-associated SpA (CD-SpA) compared to CD alone...

A 32 year old woman presented with acute onset of abdominal pain and fever. An urgent computerised tomography (CT) of the whole abdomen showed dilated loop at the terminal ileum in the right lower abdomen with thickening of the wall and oedema. The CT was suggestive of distal small bowel obstruction at the ileum with surrounding wall oedema. Multiple biopsies taken from the terminal ileum and colon on colonoscopy were all unremarkable. She represented one-year later with a recurrence of intestinal obstruction...

BACKGROUND: There are no published large-scale epidemiologic studies regarding the prevalence of skin diseases in patients with selective immunoglobulin A (IgA) deficiency (sIgAD). The purpose of this study was to investigate the prevalence of dermatological diseases in patients with sIgAD. METHODS: This retrospective matched case-control study was based on data from the Leumit Healthcare Services data base (approximately 725,000 residents of Israel), which was searched for all subjects aged ≥12 years who had undergone serum total IgA measurements during 2004-14 for any reason...

INTRODUCTION: Primary lymphomas of the small intestine are rare. Burkitt's lymphoma (BL) occurs sporadically in adults. Nodular lymphoid hyperplasia (NLH) is a rare disorder characterized by diffuse nodular lesions, which represent hyperplastic lymphoid follicles, and it is often associated with immunodeficiency syndromes. PRESENTATION OF CASE: We present a 38-year-old male patient in a state of surgical emergency, suspected of Crohn's disease, who had an unusual combination of NLH and BL of the proximal ileum...

BACKGROUND Selective immunoglobulin A (IgA) deficiency is the most common inherited immunodeficiency disorder worldwide. An early diagnosis is advocated because of the increased risk of infections, autoimmune diseases, and allergic reactions. We investigated the usefulness of a rapid point-of-care test in detecting for IgA deficiency in a population with a previously unknown prevalence. MATERIAL AND METHODS Altogether, 1000 children aged 11-13 years from randomly selected Lithuanian schools were enrolled. A point-of-care test with a fingertip sample was used to screen for the presence of IgA deficiency in children whose parents gave consent...

DEFINITION OF THE DISEASE: Ataxia telangiectasia (A-T) is an autosomal recessive disorder primarily characterized by cerebellar degeneration, telangiectasia, immunodeficiency, cancer susceptibility and radiation sensitivity. A-T is often referred to as a genome instability or DNA damage response syndrome. EPIDEMIOLOGY: The world-wide prevalence of A-T is estimated to be between 1 in 40,000 and 1 in 100,000 live births. CLINICAL DESCRIPTION: A-T is a complex disorder with substantial variability in the severity of features between affected individuals, and at different ages...

Around 65% of primary immunodeficiencies are antibody deficiencies. Functional tests are useful tools to study B-cell functions in vitro. However, no accepted guidelines for performing and evaluating functional tests have been issued yet. Here, we report our experience on the study of B-cell functions in infancy and throughout childhood. We show that T-independent stimulation with CpG measures proliferation and differentiation potential of memory B cells. Switched memory B cells respond better than IgM memory B cells...

BACKGROUND: Primary immunodeficiencies (PID) are characterized by alteration of the components of the immune system. Humoral deficiencies represent 50%. The most common are selective IgA deficiency, Bruton agammaglobulinemia, and common variable immunodeficiency (CVID). OBJECTIVE: To describe the epidemiological and clinical characteristics of adults with humoral PID, cared for in a Primary Humoral Immunodeficiencies Clinic. METHODS: A descriptive cross-sectional study that included a year of analysis, including 35 patients with humoral PID, 31 with CVID, and 4 with Bruton agammaglobulinemia...

INTRODUCTION: The inter-relationship of Human Immunodeficiency Virus (HIV) infection and dental caries as well as Salivary Immunoglobulin-A (S-IgA) level appear to remain under explored while a manual and electronic search of the literature was made. Hence, the present study was undertaken to assess the relationship of S-IgA and dental caries status in HIV positive children. AIM: The aim of this study was to find out the relationship of S-IgA antibody with dental caries by measuring the concentration of IgA in saliva of HIV positive and negative children and determine the dental caries status in HIV positive and HIV negative children, which may help in treatment planning and prevention of the same...

Selective immunoglobulin A deficiency (SIgAD) is the most common primary antibody deficiency. Although more patients with SIgAD are asymptomatic, selected patients suffer from different clinical complications such as pulmonary infections, allergies, autoimmune diseases, gastrointestinal disorders and malignancy. Pathogenesis of SIgAD is still unknown; however, a defective terminal differentiation of B cells and defect in switching to IgA-producing plasma cells are presumed to be responsible. Furthermore, some cytogenic defects and monogenic mutations are associated with SIgAD...

We describe an interesting case of severe asthma who was not showing satisfactory response to standard treatment. Investigations revealed him to be suffering from allergic bronchopulmonary aspergillosis (ABPA). After starting systemic steroids he showed marked improvement initially only to have recurrent symptoms within a year. He was investigated further and found to have chronic pulmonary aspergillosis in the form of chronic cavitary pulmonary aspergillosis (CCPA) and aspergilloma as also the presence of selective IgA deficiency...